drivers/hwmon/lm83.c - kernel/msm-5.4 - Gitiles

 /*
  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
  *          monitoring
  * Copyright (C) 2003-2005  Jean Delvare <khali@linux-fr.org>
  *
  * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
  * a sensor chip made by National Semiconductor. It reports up to four
  * temperatures (its own plus up to three external ones) with a 1 deg
  * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
  * from National's website at:
  *   http://www.national.com/pf/LM/LM83.html
  * Since the datasheet omits to give the chip stepping code, I give it
  * here: 0x03 (at register 0xff).
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/hwmon.h>
 #include <linux/err.h>

 /*
  * Addresses to scan
  * Address is selected using 2 three-level pins, resulting in 9 possible
  * addresses.
  */

 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
 					0x29, 0x2a, 0x2b,
 					0x4c, 0x4d, 0x4e,
 					I2C_CLIENT_END };

 /*
  * Insmod parameters
  */

 I2C_CLIENT_INSMOD_1(lm83);

 /*
  * The LM83 registers
  * Manufacturer ID is 0x01 for National Semiconductor.
  */

 #define LM83_REG_R_MAN_ID		0xFE
 #define LM83_REG_R_CHIP_ID		0xFF
 #define LM83_REG_R_CONFIG		0x03
 #define LM83_REG_W_CONFIG		0x09
 #define LM83_REG_R_STATUS1		0x02
 #define LM83_REG_R_STATUS2		0x35
 #define LM83_REG_R_LOCAL_TEMP		0x00
 #define LM83_REG_R_LOCAL_HIGH		0x05
 #define LM83_REG_W_LOCAL_HIGH		0x0B
 #define LM83_REG_R_REMOTE1_TEMP		0x30
 #define LM83_REG_R_REMOTE1_HIGH		0x38
 #define LM83_REG_W_REMOTE1_HIGH		0x50
 #define LM83_REG_R_REMOTE2_TEMP		0x01
 #define LM83_REG_R_REMOTE2_HIGH		0x07
 #define LM83_REG_W_REMOTE2_HIGH		0x0D
 #define LM83_REG_R_REMOTE3_TEMP		0x31
 #define LM83_REG_R_REMOTE3_HIGH		0x3A
 #define LM83_REG_W_REMOTE3_HIGH		0x52
 #define LM83_REG_R_TCRIT		0x42
 #define LM83_REG_W_TCRIT		0x5A

 /*
  * Conversions and various macros
  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  */

 #define TEMP_FROM_REG(val)	((val) * 1000)
 #define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
 				 (val) >= 127000 ? 127 : \
 				 (val) < 0 ? ((val) - 500) / 1000 : \
 				 ((val) + 500) / 1000)

 static const u8 LM83_REG_R_TEMP[] = {
 	LM83_REG_R_LOCAL_TEMP,
 	LM83_REG_R_REMOTE1_TEMP,
 	LM83_REG_R_REMOTE2_TEMP,
 	LM83_REG_R_REMOTE3_TEMP,
 	LM83_REG_R_LOCAL_HIGH,
 	LM83_REG_R_REMOTE1_HIGH,
 	LM83_REG_R_REMOTE2_HIGH,
 	LM83_REG_R_REMOTE3_HIGH,
 	LM83_REG_R_TCRIT,
 };

 static const u8 LM83_REG_W_HIGH[] = {
 	LM83_REG_W_LOCAL_HIGH,
 	LM83_REG_W_REMOTE1_HIGH,
 	LM83_REG_W_REMOTE2_HIGH,
 	LM83_REG_W_REMOTE3_HIGH,
 	LM83_REG_W_TCRIT,
 };

 /*
  * Functions declaration
  */

 static int lm83_attach_adapter(struct i2c_adapter *adapter);
 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
 static int lm83_detach_client(struct i2c_client *client);
 static struct lm83_data *lm83_update_device(struct device *dev);

 /*
  * Driver data (common to all clients)
  */

 static struct i2c_driver lm83_driver = {
 	.owner		= THIS_MODULE,
 	.name		= "lm83",
 	.id		= I2C_DRIVERID_LM83,
 	.flags		= I2C_DF_NOTIFY,
 	.attach_adapter	= lm83_attach_adapter,
 	.detach_client	= lm83_detach_client,
 };

 /*
  * Client data (each client gets its own)
  */

 struct lm83_data {
 	struct i2c_client client;
 	struct class_device *class_dev;
 	struct semaphore update_lock;
 	char valid; /* zero until following fields are valid */
 	unsigned long last_updated; /* in jiffies */

 	/* registers values */
 	s8 temp[9];	/* 0..3: input 1-4,
 			   4..7: high limit 1-4,
 			   8   : critical limit */
 	u16 alarms; /* bitvector, combined */
 };

 /*
  * Sysfs stuff
  */

 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm83_data *data = lm83_update_device(dev);
 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 }

 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 			const char *buf, size_t count)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct i2c_client *client = to_i2c_client(dev);
 	struct lm83_data *data = i2c_get_clientdata(client);
 	long val = simple_strtol(buf, NULL, 10);
 	int nr = attr->index;

 	down(&data->update_lock);
 	data->temp[nr] = TEMP_TO_REG(val);
 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 				  data->temp[nr]);
 	up(&data->update_lock);
 	return count;
 }

 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
 			   char *buf)
 {
 	struct lm83_data *data = lm83_update_device(dev);
 	return sprintf(buf, "%d\n", data->alarms);
 }

 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
 	set_temp, 4);
 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
 	set_temp, 5);
 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
 	set_temp, 6);
 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
 	set_temp, 7);
 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
 	set_temp, 8);
 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

 /*
  * Real code
  */

 static int lm83_attach_adapter(struct i2c_adapter *adapter)
 {
 	if (!(adapter->class & I2C_CLASS_HWMON))
 		return 0;
 	return i2c_probe(adapter, &addr_data, lm83_detect);
 }

 /*
  * The following function does more than just detection. If detection
  * succeeds, it also registers the new chip.
  */
 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
 {
 	struct i2c_client *new_client;
 	struct lm83_data *data;
 	int err = 0;
 	const char *name = "";

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		goto exit;

 	if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
 		err = -ENOMEM;
 		goto exit;
 	}
 	memset(data, 0, sizeof(struct lm83_data));

 	/* The common I2C client data is placed right after the
 	 * LM83-specific data. */
 	new_client = &data->client;
 	i2c_set_clientdata(new_client, data);
 	new_client->addr = address;
 	new_client->adapter = adapter;
 	new_client->driver = &lm83_driver;
 	new_client->flags = 0;

 	/* Now we do the detection and identification. A negative kind
 	 * means that the driver was loaded with no force parameter
 	 * (default), so we must both detect and identify the chip
 	 * (actually there is only one possible kind of chip for now, LM83).
 	 * A zero kind means that the driver was loaded with the force
 	 * parameter, the detection step shall be skipped. A positive kind
 	 * means that the driver was loaded with the force parameter and a
 	 * given kind of chip is requested, so both the detection and the
 	 * identification steps are skipped. */

 	/* Default to an LM83 if forced */
 	if (kind == 0)
 		kind = lm83;

 	if (kind < 0) { /* detection */
 		if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
 		    & 0xA8) != 0x00) ||
 		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
 		    & 0x48) != 0x00) ||
 		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
 		    & 0x41) != 0x00)) {
 			dev_dbg(&adapter->dev,
 			    "LM83 detection failed at 0x%02x.\n", address);
 			goto exit_free;
 		}
 	}

 	if (kind <= 0) { /* identification */
 		u8 man_id, chip_id;

 		man_id = i2c_smbus_read_byte_data(new_client,
 		    LM83_REG_R_MAN_ID);
 		chip_id = i2c_smbus_read_byte_data(new_client,
 		    LM83_REG_R_CHIP_ID);

 		if (man_id == 0x01) { /* National Semiconductor */
 			if (chip_id == 0x03) {
 				kind = lm83;
 			}
 		}

 		if (kind <= 0) { /* identification failed */
 			dev_info(&adapter->dev,
 			    "Unsupported chip (man_id=0x%02X, "
 			    "chip_id=0x%02X).\n", man_id, chip_id);
 			goto exit_free;
 		}
 	}

 	if (kind == lm83) {
 		name = "lm83";
 	}

 	/* We can fill in the remaining client fields */
 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
 	data->valid = 0;
 	init_MUTEX(&data->update_lock);

 	/* Tell the I2C layer a new client has arrived */
 	if ((err = i2c_attach_client(new_client)))
 		goto exit_free;

 	/*
 	 * Initialize the LM83 chip
 	 * (Nothing to do for this one.)
 	 */

 	/* Register sysfs hooks */
 	data->class_dev = hwmon_device_register(&new_client->dev);
 	if (IS_ERR(data->class_dev)) {
 		err = PTR_ERR(data->class_dev);
 		goto exit_detach;
 	}

 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp1_input.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp2_input.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp3_input.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp4_input.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp1_max.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp2_max.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp3_max.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp4_max.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp1_crit.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp2_crit.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp3_crit.dev_attr);
 	device_create_file(&new_client->dev,
 			   &sensor_dev_attr_temp4_crit.dev_attr);
 	device_create_file(&new_client->dev, &dev_attr_alarms);

 	return 0;

 exit_detach:
 	i2c_detach_client(new_client);
 exit_free:
 	kfree(data);
 exit:
 	return err;
 }

 static int lm83_detach_client(struct i2c_client *client)
 {
 	struct lm83_data *data = i2c_get_clientdata(client);
 	int err;

 	hwmon_device_unregister(data->class_dev);

 	if ((err = i2c_detach_client(client)))
 		return err;

 	kfree(data);
 	return 0;
 }

 static struct lm83_data *lm83_update_device(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct lm83_data *data = i2c_get_clientdata(client);

 	down(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 		int nr;

 		dev_dbg(&client->dev, "Updating lm83 data.\n");
 		for (nr = 0; nr < 9; nr++) {
 			data->temp[nr] =
 			    i2c_smbus_read_byte_data(client,
 			    LM83_REG_R_TEMP[nr]);
 		}
 		data->alarms =
 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 		    << 8);

 		data->last_updated = jiffies;
 		data->valid = 1;
 	}

 	up(&data->update_lock);

 	return data;
 }

 static int __init sensors_lm83_init(void)
 {
 	return i2c_add_driver(&lm83_driver);
 }

 static void __exit sensors_lm83_exit(void)
 {
 	i2c_del_driver(&lm83_driver);
 }

 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 MODULE_DESCRIPTION("LM83 driver");
 MODULE_LICENSE("GPL");

 module_init(sensors_lm83_init);
 module_exit(sensors_lm83_exit);
	/*
	* lm83.c - Part of lm_sensors, Linux kernel modules for hardware
	* monitoring
	* Copyright (C) 2003-2005 Jean Delvare <khali@linux-fr.org>
	*
	* Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
	* a sensor chip made by National Semiconductor. It reports up to four
	* temperatures (its own plus up to three external ones) with a 1 deg
	* resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
	* from National's website at:
	* http://www.national.com/pf/LM/LM83.html
	* Since the datasheet omits to give the chip stepping code, I give it
	* here: 0x03 (at register 0xff).
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/jiffies.h>
	#include <linux/i2c.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/hwmon.h>
	#include <linux/err.h>

	/*
	* Addresses to scan
	* Address is selected using 2 three-level pins, resulting in 9 possible
	* addresses.
	*/

	static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
	0x29, 0x2a, 0x2b,
	0x4c, 0x4d, 0x4e,
	I2C_CLIENT_END };

	/*
	* Insmod parameters
	*/

	I2C_CLIENT_INSMOD_1(lm83);

	/*
	* The LM83 registers
	* Manufacturer ID is 0x01 for National Semiconductor.
	*/

	#define LM83_REG_R_MAN_ID 0xFE
	#define LM83_REG_R_CHIP_ID 0xFF
	#define LM83_REG_R_CONFIG 0x03
	#define LM83_REG_W_CONFIG 0x09
	#define LM83_REG_R_STATUS1 0x02
	#define LM83_REG_R_STATUS2 0x35
	#define LM83_REG_R_LOCAL_TEMP 0x00
	#define LM83_REG_R_LOCAL_HIGH 0x05
	#define LM83_REG_W_LOCAL_HIGH 0x0B
	#define LM83_REG_R_REMOTE1_TEMP 0x30
	#define LM83_REG_R_REMOTE1_HIGH 0x38
	#define LM83_REG_W_REMOTE1_HIGH 0x50
	#define LM83_REG_R_REMOTE2_TEMP 0x01
	#define LM83_REG_R_REMOTE2_HIGH 0x07
	#define LM83_REG_W_REMOTE2_HIGH 0x0D
	#define LM83_REG_R_REMOTE3_TEMP 0x31
	#define LM83_REG_R_REMOTE3_HIGH 0x3A
	#define LM83_REG_W_REMOTE3_HIGH 0x52
	#define LM83_REG_R_TCRIT 0x42
	#define LM83_REG_W_TCRIT 0x5A

	/*
	* Conversions and various macros
	* The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
	*/

	#define TEMP_FROM_REG(val) ((val) * 1000)
	#define TEMP_TO_REG(val) ((val) <= -128000 ? -128 : \
	(val) >= 127000 ? 127 : \
	(val) < 0 ? ((val) - 500) / 1000 : \
	((val) + 500) / 1000)

	static const u8 LM83_REG_R_TEMP[] = {
	LM83_REG_R_LOCAL_TEMP,
	LM83_REG_R_REMOTE1_TEMP,
	LM83_REG_R_REMOTE2_TEMP,
	LM83_REG_R_REMOTE3_TEMP,
	LM83_REG_R_LOCAL_HIGH,
	LM83_REG_R_REMOTE1_HIGH,
	LM83_REG_R_REMOTE2_HIGH,
	LM83_REG_R_REMOTE3_HIGH,
	LM83_REG_R_TCRIT,
	};

	static const u8 LM83_REG_W_HIGH[] = {
	LM83_REG_W_LOCAL_HIGH,
	LM83_REG_W_REMOTE1_HIGH,
	LM83_REG_W_REMOTE2_HIGH,
	LM83_REG_W_REMOTE3_HIGH,
	LM83_REG_W_TCRIT,
	};

	/*
	* Functions declaration
	*/

	static int lm83_attach_adapter(struct i2c_adapter *adapter);
	static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
	static int lm83_detach_client(struct i2c_client *client);
	static struct lm83_data lm83_update_device(struct device dev);

	/*
	* Driver data (common to all clients)
	*/

	static struct i2c_driver lm83_driver = {
	.owner = THIS_MODULE,
	.name = "lm83",
	.id = I2C_DRIVERID_LM83,
	.flags = I2C_DF_NOTIFY,
	.attach_adapter = lm83_attach_adapter,
	.detach_client = lm83_detach_client,
	};

	/*
	* Client data (each client gets its own)
	*/

	struct lm83_data {
	struct i2c_client client;
	struct class_device *class_dev;
	struct semaphore update_lock;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* registers values */
	s8 temp[9]; /* 0..3: input 1-4,
	4..7: high limit 1-4,
	8 : critical limit */
	u16 alarms; /* bitvector, combined */
	};

	/*
	* Sysfs stuff
	*/

	static ssize_t show_temp(struct device dev, struct device_attribute devattr,
	char *buf)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct lm83_data *data = lm83_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
	}

	static ssize_t set_temp(struct device dev, struct device_attribute devattr,
	const char *buf, size_t count)
	{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct lm83_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int nr = attr->index;

	down(&data->update_lock);
	data->temp[nr] = TEMP_TO_REG(val);
	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
	data->temp[nr]);
	up(&data->update_lock);
	return count;
	}

	static ssize_t show_alarms(struct device dev, struct device_attribute dummy,
	char *buf)
	{
	struct lm83_data *data = lm83_update_device(dev);
	return sprintf(buf, "%d\n", data->alarms);
	}

	static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
	static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
	static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
	static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
	static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR \| S_IRUGO, show_temp,
	set_temp, 4);
	static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR \| S_IRUGO, show_temp,
	set_temp, 5);
	static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR \| S_IRUGO, show_temp,
	set_temp, 6);
	static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR \| S_IRUGO, show_temp,
	set_temp, 7);
	static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
	static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
	static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR \| S_IRUGO, show_temp,
	set_temp, 8);
	static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
	static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

	/*
	* Real code
	*/

	static int lm83_attach_adapter(struct i2c_adapter *adapter)
	{
	if (!(adapter->class & I2C_CLASS_HWMON))
	return 0;
	return i2c_probe(adapter, &addr_data, lm83_detect);
	}

	/*
	* The following function does more than just detection. If detection
	* succeeds, it also registers the new chip.
	*/
	static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
	{
	struct i2c_client *new_client;
	struct lm83_data *data;
	int err = 0;
	const char *name = "";

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	goto exit;

	if (!(data = kmalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
	err = -ENOMEM;
	goto exit;
	}
	memset(data, 0, sizeof(struct lm83_data));

	/* The common I2C client data is placed right after the
	* LM83-specific data. */
	new_client = &data->client;
	i2c_set_clientdata(new_client, data);
	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &lm83_driver;
	new_client->flags = 0;

	/* Now we do the detection and identification. A negative kind
	* means that the driver was loaded with no force parameter
	* (default), so we must both detect and identify the chip
	* (actually there is only one possible kind of chip for now, LM83).
	* A zero kind means that the driver was loaded with the force
	* parameter, the detection step shall be skipped. A positive kind
	* means that the driver was loaded with the force parameter and a
	* given kind of chip is requested, so both the detection and the
	* identification steps are skipped. */

	/* Default to an LM83 if forced */
	if (kind == 0)
	kind = lm83;

	if (kind < 0) { /* detection */
	if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
	& 0xA8) != 0x00) \|\|
	((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
	& 0x48) != 0x00) \|\|
	((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
	& 0x41) != 0x00)) {
	dev_dbg(&adapter->dev,
	"LM83 detection failed at 0x%02x.\n", address);
	goto exit_free;
	}
	}

	if (kind <= 0) { /* identification */
	u8 man_id, chip_id;

	man_id = i2c_smbus_read_byte_data(new_client,
	LM83_REG_R_MAN_ID);
	chip_id = i2c_smbus_read_byte_data(new_client,
	LM83_REG_R_CHIP_ID);

	if (man_id == 0x01) { /* National Semiconductor */
	if (chip_id == 0x03) {
	kind = lm83;
	}
	}

	if (kind <= 0) { /* identification failed */
	dev_info(&adapter->dev,
	"Unsupported chip (man_id=0x%02X, "
	"chip_id=0x%02X).\n", man_id, chip_id);
	goto exit_free;
	}
	}

	if (kind == lm83) {
	name = "lm83";
	}

	/* We can fill in the remaining client fields */
	strlcpy(new_client->name, name, I2C_NAME_SIZE);
	data->valid = 0;
	init_MUTEX(&data->update_lock);

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(new_client)))
	goto exit_free;

	/*
	* Initialize the LM83 chip
	* (Nothing to do for this one.)
	*/

	/* Register sysfs hooks */
	data->class_dev = hwmon_device_register(&new_client->dev);
	if (IS_ERR(data->class_dev)) {
	err = PTR_ERR(data->class_dev);
	goto exit_detach;
	}

	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp1_input.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp2_input.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp3_input.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp4_input.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp1_max.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp2_max.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp3_max.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp4_max.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp1_crit.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp2_crit.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp3_crit.dev_attr);
	device_create_file(&new_client->dev,
	&sensor_dev_attr_temp4_crit.dev_attr);
	device_create_file(&new_client->dev, &dev_attr_alarms);

	return 0;

	exit_detach:
	i2c_detach_client(new_client);
	exit_free:
	kfree(data);
	exit:
	return err;
	}

	static int lm83_detach_client(struct i2c_client *client)
	{
	struct lm83_data *data = i2c_get_clientdata(client);
	int err;

	hwmon_device_unregister(data->class_dev);

	if ((err = i2c_detach_client(client)))
	return err;

	kfree(data);
	return 0;
	}

	static struct lm83_data lm83_update_device(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm83_data *data = i2c_get_clientdata(client);

	down(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ * 2) \|\| !data->valid) {
	int nr;

	dev_dbg(&client->dev, "Updating lm83 data.\n");
	for (nr = 0; nr < 9; nr++) {
	data->temp[nr] =
	i2c_smbus_read_byte_data(client,
	LM83_REG_R_TEMP[nr]);
	}
	data->alarms =
	i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
	+ (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
	<< 8);

	data->last_updated = jiffies;
	data->valid = 1;
	}

	up(&data->update_lock);

	return data;
	}

	static int __init sensors_lm83_init(void)
	{
	return i2c_add_driver(&lm83_driver);
	}

	static void __exit sensors_lm83_exit(void)
	{
	i2c_del_driver(&lm83_driver);
	}

	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
	MODULE_DESCRIPTION("LM83 driver");
	MODULE_LICENSE("GPL");

	module_init(sensors_lm83_init);
	module_exit(sensors_lm83_exit);